US3925538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing alumina monohydrate from basic aluminum nitrates
Assignee: Reynolds Metals Co
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Filing: 1974-11-06
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Granted: 1975-12-09
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Expires: 1994-11-06
Abstract
Abstract Process for producing alumina monohydrate and aluminum nitrate from basic aluminum nitrates by preparing an aqueous solution of the basic aluminum nitrate having a nitrate concentration low enough to prevent solution of Al2O3, heating the solution under autogenous pressure to convert the free alumina in the basic aluminum nitrate to solid alumina monohydrate, and recovering the solid alumina monohydrate.
Inventors
- 👤 Charles P Bruen
- 👤 Donald H Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:10
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/66; C01F7/02; C01F7/30; C01F7/308
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
87 words
IN A PROCESS FOR RECOVERING ALUMINA MONOHYDRATE AND ALUMINUM NITRATE FROM BASE ALUMINUM NITRATES PREPAARED BY MELTING ALUMINUM NITRATE NONAHYDRATE, PARTIALLY DENITRIFYING SAID MOLTEN ALUMINUM NITRATE NONAHYDRATE BY HEATING IT TO A TEMPERATURE ABOVE ITS DECOMPOSITION TEMPERATURE BUT NOT ABOVE ABOUT 235*C. UNDER SUPERATMOSPHERIC PRESSURE OF AT LEAST ABOUT 25 PSIG AND SUFFICIENT TO MAINTAIN SAID DECOMPOSITION TEMPERATURE, WHILE REMOVING GASEOUS NITRIC ACID DECOMPOSITION PRODUCTS UNTIL BEETWEEN ABOUT 45% AND ABOUT 55% OF THE HNO3 OF THE ALUMINUM NITRATE NONAHYDRATE HAS BEEN REMOVED, THE STEP WHICH COMPRISE
Claim 2
Dependent Claim
87 words
IN A PROCESS FOR RECOVERING ALUMINA MONOHYDRATE AND ALUMINUM NITRATE FROM BASE ALUMINUM NITRATES PREPAARED BY MELTING ALUMINUM NITRATE NONAHYDRATE, PARTIALLY DENITRIFYING SAID MOLTEN ALUMINUM NITRATE NONAHYDRATE BY HEATING IT TO A TEMPERATURE ABOVE ITS DECOMPOSITION TEMPERATURE BUT NOT ABOVE ABOUT 235*C. UNDER SUPERATMOSPHERIC PRESSURE OF AT LEAST ABOUT 25 PSIG AND SUFFICIENT TO MAINTAIN SAID DECOMPOSITION TEMPERATURE, WHILE REMOVING GASEOUS NITRIC ACID DECOMPOSITION PRODUCTS UNTIL BEETWEEN ABOUT 45% AND ABOUT 55% OF THE HNO3 OF THE ALUMINUM NITRATE NONAHYDRATE HAS BEEN REMOVED, THE STEP WHICH COMPRISE
Claim 3
Dependent Claim
10 words
ADDING TO A BASIC ALUMINUM NITATE HAVING THE EMPIRICAL FORMULA
Claim 4
Dependent Claim
10 words
ADDING TO A BASIC ALUMINUM NITATE HAVING THE EMPIRICAL FORMULA
References Cited (Backward Citations)
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Cited
US2196016A
Cited
US3056747A
Cited
US2915475A
Cited
US3387921A
Cited
US3366446A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |